title: Collateralization of an occluded internal carotid artery via a vas vasorum.
abstract: BACKGROUND
  Reopening of an occluded internal carotid artery (ICA) is often seen in dissections but only rarely occurs in atherothrombotic occlusion of the internal carotid artery.
  
  
  METHODS
  A 60-year-old man suffered a minor stroke with dysphasia in March 1995. Color-coded duplex ultrasonography of his neck arteries revealed a left ICA occlusion. He was placed on a regimen of aspirin and followed up clinically and with ultrasonography. At follow-up 18 months later, the patient was asymptomatic. On duplex ultrasonography his left occluded ICA was found to be reopened, with a residual, proximal, high-grade stenosis. However, intra-arterial digital subtraction angiography demonstrated a persistent ICA occlusion and a vas vasorum originating from the carotid bulb and draining into the ICA distal to the occlusion.
  
  
  CONCLUSIONS
  The rare collateralization of an occluded ICA by vasa vasorum seems to take several months. It can be a pitfall in the ultrasound diagnosis of carotid artery occlusive disease.
authors.affiliation: Department of Neurology, University of Münster, Germany. kemeny@uni-muenster.de
authors.forename: V
authors.initials: V
authors.lastname: Kemény
authors.forename: D W
authors.initials: DW
authors.lastname: Droste
authors.forename: D G
authors.initials: DG
authors.lastname: Nabavi
authors.forename: G
authors.initials: G
authors.lastname: Schulte-Altedorneburg
authors.forename: G
authors.initials: G
authors.lastname: Schuierer
authors.forename: E B
authors.initials: EB
authors.lastname: Ringelstein
mesh_terms: D002343:Carotid Artery, Internal; D016893:Carotid Stenosis / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D002561:Cerebrovascular Disorders / Q000150:complications / Q000000981:diagnostic imaging*; D003097:Collateral Circulation; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D017585:Ultrasonography, Doppler, Transcranial